Abstract:

A data communications network, for which presence information is
maintained for wireless data communication devices forming nodes of the
network, includes: a presence server; and a plurality of nodes formed by
the wireless data communication devices, each of the devices configured
to send periodic check-in messages to the presence server. The presence
server is configured to send an acknowledgment in response to a check-in
message. Each of the wireless data communication devices is configured to
reset a timer associated with the sending of the check-in messages by it
upon (i) communicating, as an intermediate node, a check-in message
originating at another node, and (ii) communicating, as an intermediate
node, a corresponding acknowledgment originating at the presence server.
The presence server is configured to update presence information of
wireless data communication device from which a check-in message
originates and each intermediate node.

Claims:

1-16. (canceled)

17. A method of maintaining presence information associated with a
wireless data communication device of a data communications network,
comprising the steps of:(a) communicating a message from a first node of
the data communications network to a gateway device along a pathway, the
pathway including the wireless data communication device as an
intermediary node of the pathway;(b) including with the message the
pathway by which the message is communicated in the wireless data
communication device;(c) storing, in a computer readable medium at the
gateway device, information representing the pathway;(d) updating, at the
gateway device, presence information of the wireless data communication
device;(e) communicating an acknowledgment of the message to the first
node along the reverse pathway; and(f) upon communicating the
acknowledgement of the message by the wireless data communication device
in said step (e), resetting a timer used by the wireless data
communication device to trigger the sending of a presence indication of
the wireless data communication device to the gateway device.

18. The method of claim 17, further comprising the step of communicating,
by the gateway device, to an application of a client device, the message
from the first node.

19. The method of claim 17, further comprising the step of receiving, by
the gateway device, an acknowledgement of the message from the
application of the client device for communicating to the first node.

20. The method of claim 17, wherein the wireless data communication device
is configured to communicate a check-in message when the timer reaches a
certain value.

21. The method of claim 17, wherein the gateway device, the first node,
and the wireless data communication device forming an intermediate node
are part of a network utilizing class based networking.

22. The method of claim 17, wherein the first node and the wireless data
communication device forming an intermediary node utilize wake-up
technology.

23. The method of claim 17, further comprising, prior to communicating a
message from a first node, registering with the gateway device by the
wireless data communication device.

24. The method of claim 17, wherein the gateway device, the first node,
and the wireless data communication device forming an intermediary node
are part of a mesh network.

25. The method of claim 17, wherein said step of resetting a timer occurs
contemporaneously with the step of communicating the acknowledgment.

29. A method of indicating presence by a wireless data communication
device that forms a node in a data communications network, comprising the
steps of:(a) receiving, at the wireless data communication device, a
message originating at a first node and addressed to a gateway device;(b)
storing, in a computer readable medium of the wireless data communication
device, information associated with the message;(c) communicating, by the
wireless data communication device, for delivery to gateway device, the
message to another node of the data communications network;(d) receiving,
at the wireless data communication device, an acknowledgment of the
message by the gateway device;(e) resetting a timer at the wireless data
communication device; and(f) communicating, by the wireless data
communication device, for delivery to the first node, the acknowledgment
of the message by the gateway device;(g) wherein the wireless data
communication device is configured to communicate a message to the
gateway device indicating the presence of the wireless data communication
device as a node in the data communications network at predetermined
intervals based on the timer.

30. The method of claim 29, wherein said step of communicating the message
to the gateway device comprises communicating the message directly to the
gateway device.

31. The method of claim 29, wherein said step of communicating the message
to the gateway device comprises communicating the message indirectly to
the gateway device via one or more other nodes.

32. The method of claim 29, wherein said step of communicating the
acknowledgment of the message to the first node comprises communicating
the message directly to the first node.

33. The method of claim 29, wherein said step of communicating the
acknowledgment of the message to the first node comprises communicating
the message indirectly to the first node via one or more other nodes.

34. The method of claim 29, further comprising the step of, prior to said
step of receiving a message originating at a first node, registering, by
the intermediary node, with the gateway device.

35. The method of claim 29, wherein the gateway device, the first node,
and the intermediary node are part of a mesh network.

36. The method of claim 29, wherein the gateway device, the first node,
and the intermediary node are part of a network utilizing class based
networking.

[0031]All of the material in this patent document is subject to copyright
protection under the copyright laws of the United States and other
countries. The copyright owner has no objection to the facsimile
reproduction by anyone of the patent document or the patent disclosure,
as it appears in official governmental records but, otherwise, all other
copyright rights whatsoever are reserved.

BACKGROUND

[0032]For background and contextual information, the above identified
published patent applications and patents are referenced. Additionally,
it is noted that some conventional systems for tracking and/or monitoring
assets (herein generally referred to as "asset tracking systems") utilize
wireless tags that generally respond to any broadcast that is made. The
wireless tags usually are passive, and the responses that the passive
wireless tags make are often referred to as "chirps."

[0033]More sophisticated conventional asset tracking systems utilize
semi-passive wireless tags and/or active wireless tags. A semi-passive
wireless tag includes an internal power source for transmitting, and an
active wireless tag includes an internal power source for both receiving
and transmitting. Semi-passive and active wireless tags generally have
greater capabilities than passive wireless tags due to the internal power
sources. Of course, power consumption is always a concern when a wireless
tag includes an internal power source, since the internal power supply
limits the useful life of the wireless tag, after which time maintenance
is required (e.g., replacement of the internal power source).

[0034]In improved asset tracking systems, such as disclosed in U.S. Pat.
No. 6,934,540 and other of the above-incorporated patent applications and
patents, a wireless tag responds to a broadcast if the broadcast includes
a common designation matching a common designation of the wireless tag.
Such a common designation may comprise, for example, an "asset class"
associated with the wireless tag. Ad hoc networks further may be created
based on such classes, which ad hoc networks are referred to as "class
based" networks.

[0035]Class based networks (and common designation networks in general)
are beneficial because, in such networks, a communication device, such as
a wireless tag, generally only transmits a response to a broadcast if the
broadcast includes a class (or common designation) that matches a class
(or common designation) of that communication device. Indeed, in a
communication device employing a wakeup sequence of one or more of the
patent references incorporated herein by reference, such communication
device does not even process a broadcast once it is determined that the
broadcast fails to include a matching class of the communication device.
Consequently, the internal power supply of a semi-passive or active
communication device is not drained by needless processing and/or
responses to broadcasts.

[0036]In any asset tracking system, it often is important to know the
physical location of an asset. This could include knowing where the asset
is within a limited physical area, such as a warehouse; this also could
include knowing where the asset is within several different warehouses in
several different geographical locations, as well as where the asset is
during transit between such locations.

[0037]In some conventional asset tracking systems in which wireless data
communication devices are placed on the assets, a method for acquiring
visibility of the assets includes broadcasting within an area at regular
intervals in order to solicit responses from all of the wireless data
communication devices within the area. The responses from the wireless
data communication devices reveal the presence of the wireless data
communication devices and, by assumption, the presence of the assets in
the area. This method is not advantageous because the regular, repetitive
broadcasts result in an unnecessary power drain of the responding
wireless data communication devices when such devices comprise active or
semi-passive radios. Moreover, interference also can occur if a large
number of wireless data communication devices respond at the same time,
thereby making it difficult to accurately identify all of the wireless
data communication devices within the area that respond to the broadcast.

[0038]In an alternative conventional method, a timer is included with each
wireless data communication device and the wireless data communication
device is configured to transmit at periodic intervals as a function of
the timer. The wireless data communication device thereby alerts the
tracking system as to the whereabouts of the wireless data communication
device and by assumption, the asset with which it is associated. By
including timers with the wireless data communication devices, the
wireless data communication devices may transmit at different times in
order to avoid unnecessary interference. A wireless data communication
device also can be set to sleep during intervals of no transmissions and
to be awoken by the timer for making regularly scheduled transmissions.
This increases the useful life of the wireless data communication devices
because the wireless data communication devices do not consume power by
actively listening for broadcasts while sleeping.

[0039]While this alternative method permits determinations as to the
delivery and continued presence of an asset at a particular area, this
alternative method does include drawbacks. For instance, by using timers,
the wireless data communication devices are usually inaccessible by the
asset tracking system during the sleep periods. Another drawback is that
the wireless data communication devices automatically awake and transmit
without regard to their location and without regard to whether the
transmissions are actually warranted or even desired. In this respect,
during transportation on a plane, for example, a wireless data
communication device may awaken and transmit, thereby causing unwanted
interference with the operation of the plane. Preprogrammed transmissions
at regular intervals also may reveal the presence of the asset to
unauthorized persons snooping for such radio transmissions.

[0040]Yet another alternative method for determining presence is disclosed
and described in U.S. patent appl. publ. no. US 2007-0155327,
incorporated herein by reference above. In accordance with an inventive
aspect of the '327 application publication, a radio frequency (RF)
communication device operates in at least two states.

[0041]In the first state, the RF communication device responds to a radio
frequency transmission that includes data representative of an inquiry as
to the presence of RF communication devices within an area. The "data
representative of an inquiry as to the presence of radio frequency
communication devices within an area" simply may be a predefined value in
a particular format within the broadcast in accordance with a predefined
protocol. A radio frequency transmission that includes such data is
sometimes referred to therein as a "Present Broadcast." The response to
the Present Broadcast is made by the RF communication device by making a
radio frequency transmission that includes an identification of the RF
communication device. A radio frequency transmission that includes an
identification of the RF communication device making the transmission,
and that is made in response to a Present Broadcast, is sometimes
referred to therein as a "Present Response."

[0042]In the second state, the RF communication device does not respond to
a Present Broadcast with a Present Response; specifically, no response to
a Present Broadcast comprising a radio frequency transmission is made
that includes an identification of the RF communication device, and
preferably, no response to a Present Broadcast comprising a radio
frequency transmission is made at all, whether including an
identification of the RF communication device or otherwise.

[0043]The electronic components of the RF communication device are
arranged and configured such that the RF communication device enters the
second state from the first state upon responding to a Present Broadcast
with a Present Response. The electronic components further are arranged
and configured such that the RF communication device enters the first
state from the second state upon receiving, through a sensor interface
thereof, a sensor signal based on sensor-acquired data that is indicative
of a predetermined condition. The sensor signal itself may include the
sensor-acquired data or may be representative of the sensor-acquired data
and may indicate, for example, a state of the sensor or movement of the
RF communication device. In any event, such sensor signal is deemed to
provide "sensor-acquired information" through the interface. The
electronic components also further may be arranged and configured such
that the RF communication device enters the first state from the second
state upon receiving an instruction to do so, and the electronic
components further may be arranged and configured such that the RF
communication device enters the second state from the first state upon
receiving an instruction to do so. The electronic components also further
may be arranged and configured such that the RF communication device
enters the first state after a predetermined period of time has passed or
after a predetermined number of failed attempts to communicate by the RF
communication device have occurred.

[0044]While these approaches represent solutions to determining presence,
needs remain for still yet further improvements in methods for
determining presence.

[0045]This, and other needs, are addressed by one or more aspects of the
present invention.

SUMMARY

[0046]The invention of the present application generally relates to
networks, apparatus, methods and systems for determining the presence of
a radio frequency communication device within a wireless data
communications network, and especially for determining such presence in
an ad hoc wireless data communications network in which at least some
wireless data communication devices forming nodes of the network are at
least periodically mobile. In this context, the present invention
includes many aspects and features. Moreover, while many aspects and
features relate to, and are described in, the context of asset tracking
systems, the present invention is not limited to use only in asset
tracking systems, as will become apparent from the following summaries
and detailed descriptions of aspects, features, and one or more
embodiments of the present invention. Indeed, the present invention is
equally useful in remote sensor networks and the like for remote
monitoring, whether such monitoring is the monitoring of assets or
otherwise.

[0047]In a principal aspect of the invention of the present application, a
wireless two-way RF data communication device that forms a node of a data
communications network includes: a memory having stored therein an unique
identifier of the wireless two-way RF data communication device that
uniquely identifies the wireless two-way RF data communication device
within the data communications network; a receiver configured to receive
radio frequency transmissions; a transmitter configured to make radio
frequency transmissions; and electronic components arranged and
configured (i) such that the wireless two-way RF data communication
device communicates with other nodes of the data communications network
in communicating messages from originating nodes to destination nodes,
(ii) such that each message that is communicated by the wireless two-way
RF data communication device either as an originating node or an
intermediate node includes the unique identification of the wireless
two-way RF data communication device, (iii) such that the wireless
two-way RF data communication device communicates a presence message to a
presence server at routine intervals based on a chronometer; and (iv)
such that the measurement of the time until the next check-in message is
to be sent by the wireless two-way RF data communication device is reset
upon, (A) communicating, as an intermediate node, a message originating
at another node of the data communications network, and (B) receiving,
for deliver to the originating node of the message, an acknowledgement of
receipt by the presence server for such message. The message of the
originating node may itself be a check-in message or another message.

[0048]In a feature, the electronic components of the wireless two-way RF
data communication device are further arranged and configured such that
each message that is communicated by the wireless two-way RF data
communication device includes the unique identification of each
intermediate node by which the message has been communicated in the data
communications network.

[0049]In a feature, the electronic components of the wireless two-way RF
data communication device are further arranged and configured such that
each message that is communicated by the wireless two-way RF data
communication device includes the unique identification of the
originating node for the message in the data communications network.

[0050]In a principal aspect of the invention of the present application, a
data communications network includes: a plurality of wireless two-way
radio frequency (RF) data communication devices, each wireless two-way RF
data communication device forming a node of the data communications
network and each wireless two-way RF data communication device including
a memory having stored therein an unique identifier of the wireless
two-way RF data communication device; wherein each wireless two-way RF
data communication device comprises, (i) a receiver configured to receive
radio frequency transmissions, (ii) a transmitter configured to make
radio frequency transmissions, and (iii) electronic components arranged
and configured (A) such that the wireless two-way RF data communication
device communicates with other nodes of the data communications network
in communicating messages from originating nodes to destination nodes,
(B) such that each message that is communicated by the wireless two-way
RF data communication device, either as an originating node or an
intermediate node, includes the unique identification of the wireless
two-way RF data communication device, whereby a pathway by which each
message is communicated in the data communications network is included
with the message as the message is communicated in the data
communications network, (C) such that the wireless two-way RF data
communication device communicates a presence message to a presence server
at routine intervals based on a chronometer, and (D) such that the
measurement of the time until the next check-in message is to be sent by
the wireless two-way RF data communication device is reset upon, (I)
communicating, as an intermediate node, a message originating at another
node of the data communications network, and (II) receiving, for deliver
to the originating node of the message, an acknowledgement of receipt by
the presence server for such message. The message of the originating node
may itself be a check-in message or another message.

[0051]In a feature, the identification of an intermediate node of the
pathway by which the electronic message has been communicated is added to
the pathway information by an intermediate node.

[0052]In a feature, each node comprises a wireless radio-frequency data
communication device having a transmitter and a receiver that
collectively receive and transmit information wirelessly.

[0053]In a feature, each wireless two-way RF data communication device
comprises a standards-based data packet radio component that includes
both said receiver and said transmitter of the respective wireless
two-way RF data communication device.

[0054]In a feature, the information is wirelessly communicated in data
packets.

[0055]In a feature, the data communication device includes an interface
for communicating with a sensor for receiving sensor-acquired data.

[0056]In a feature, the data communication device is attached to an asset
for monitoring and tracking of the asset.

[0057]In a feature, the data communication device is permanently affixed
to a structure for monitoring and/or tracking assets that come within a
proximity thereto.

[0058]In a feature, the communication includes a message identification
that is unique to the message being communicated within the data
communications network.

[0059]In a feature, each communication of a message within the data
communications network includes a predetermined pathway by which the
message is to be communicated.

[0060]In a principal aspect of the invention of the present application,
and with respect to the context of a data network comprising a plurality
of wireless two-way radio frequency (RF) data communication devices, each
wireless two-way RF data communication device forming a node of the data
communications network, a method of tracking a pathway by which a message
is communicated within a data communications network includes the steps
of: maintaining a unique identification of each of the plurality of
wireless two-way RF data communication devices that form a node of the
data communications network; and for each wireless two-way RF data
communication device that communicates a message in the data
communications network, including with the message the unique
identification of the wireless two-way RF data communication device such
that the pathway by which the message is sent from an originating node to
a destination node is communicated to the destination node upon delivery
of the message to the destination node, and wherein each wireless two-way
RF data communication device performs the steps of, (i) communicating a
message from a first node of the data communications network to a gateway
device along a pathway, the pathway including the wireless data
communication device as an intermediary node of the pathway, (ii)
including with the message the pathway by which the message is
communicated in the wireless data communication device, (iii) storing, in
a computer readable medium at the gateway device, information
representing the pathway, (iv) updating, at the gateway device, presence
information of the wireless data communication device, (v) communicating
an acknowledgment of the message to the first node along the reverse
pathway, and (vi) upon communicating the acknowledgement of the message
by the wireless data communication device in said step (f), resetting a
timer used by the wireless data communication device to trigger the
sending of a presence indication of the wireless data communication
device to the gateway device.

[0061]In a feature, each wireless two-way RF data communication device
that comprises an intermediate node with respect to communicating a
message from an originating node to a destination node in the data
communications network includes with the message its unique
identification when communicating the message to the next subsequent
node.

[0062]In a feature, each node in the data communications network that
receives a communication of a message from a wireless two-way RF data
communication device includes, with the message, the unique
identification of the wireless two-way RF data communication device from
which the message is communicated.

[0063]In a principal aspect of the invention of the present application, a
method of maintaining presence information associated with a wireless
data communication device of a data communications network, comprising
the steps of: communicating a message from a first node of the data
communications network to a gateway device along a pathway, the pathway
including the wireless data communication device as an intermediary node
of the pathway; including with the message the pathway by which the
message is communicated in the wireless data communication device;
storing, in a computer readable medium at the gateway device, information
representing the pathway; updating, at the gateway device, presence
information of the wireless data communication device; communicating an
acknowledgment of the message to the first node along the reverse
pathway; and upon communicating the acknowledgement of the message by the
wireless data communication device in said step (f), resetting a timer
used by the wireless data communication device to trigger the sending of
a presence indication of the wireless data communication device to the
gateway device.

[0064]In a feature, the method further comprises the step of
communicating, by the gateway device, to an application of a client
device, the message from the first node.

[0065]In a feature, the method further comprises the step of receiving, by
the gateway device, an acknowledgement of the message from the
application of the client device for communicating to the first node.

[0066]In a feature, the wireless data communication device is configured
to communicate a check-in message when the timer reaches a certain value.

[0067]In a feature, the gateway device, the first node, and the wireless
data communication device forming an intermediate node are part of a
network utilizing class based networking.

[0068]In a feature, the first node and the wireless data communication
device forming an intermediary node utilize wake-up technology.

[0069]In a feature, the method further comprises, prior to communicating a
message from a first node, registering with the gateway device by the
wireless data communication device.

[0070]In a feature, the gateway device, the first node, and the wireless
data communication device forming an intermediary node are part of a mesh
network.

[0071]In a feature, said step of resetting a timer occurs
contemporaneously with the step of communicating the acknowledgment.

[0072]In a feature, the gateway device comprises a gateway server.

[0073]In a feature, said step of communicating to a client device
comprises communicating over the Internet.

[0075]In a principal aspect of the invention of the present application, a
method of indicating presence by a wireless data communication device
that forms a node in a data communications network, comprising the steps
of: receiving, at the wireless data communication device, a message
originating at a first node and addressed to a gateway device; storing,
in a computer readable medium of the wireless data communication device,
information associated with the message; communicating, by the wireless
data communication device, for delivery to gateway device, the message to
another node of the data communications network; receiving, at the
wireless data communication device, an acknowledgment of the message by
the gateway device; resetting a timer at the wireless data communication
device; and communicating, by the wireless data communication device, for
delivery to the first node, the acknowledgment of the message by the
gateway device; wherein the wireless data communication device is
configured to communicate a message to the gateway device indicating the
presence of the wireless data communication device as a node in the data
communications network at predetermined intervals based on the timer.

[0076]In a feature, said step of communicating the message to the gateway
device comprises communicating the message directly to the gateway
device.

[0077]In a feature, said step of communicating the message to the gateway
device comprises communicating the message indirectly to the gateway
device via one or more other nodes.

[0078]In a feature, said step of communicating the acknowledgment of the
message to the first node comprises communicating the message directly to
the first node.

[0079]In a feature, said step of communicating the acknowledgment of the
message to the first node comprises communicating the message indirectly
to the first node via one or more other nodes.

[0080]In a feature, the method further comprises the step of, prior to
said step of receiving a message originating at a first node,
registering, by the intermediary node, with the gateway device.

[0081]In a feature, the gateway device, the first node, and the
intermediary node are part of a mesh network.

[0082]In a feature, the gateway device, the first node, and the
intermediary node are part of a network utilizing class based networking.

[0083]In a feature, the first node and the intermediary node utilize
wake-up technology.

[0084]In a principal aspect of the invention of the present application, a
data communications network for which presence information is maintained
for wireless data communication devices forming nodes of the network, the
data communications network comprising: a presence server configured to
communicate an acknowledgment in response to a check-in message; a
plurality of outer nodes configured to send periodic check-in messages to
the presence server; and a plurality of inner nodes configured to send
periodic check-in messages to the presence server; (d) wherein a
communication from one of the plurality of outer nodes to the presence
server is communicated by at least one of the plurality of inner nodes as
an intermediate node; wherein each of the plurality of inner nodes is
configured to reset a timer associated with the sending of the check-in
messages upon, (i) communicating, as an intermediate node, a check-in
message originating at one of the outer nodes, and (ii) communicating, as
an intermediate node, a corresponding acknowledgment originating at the
presence server; and (f) wherein the presence server is configured to,
(i) update presence information associated with one of the plurality of
outer nodes in response to receiving a check-in message originating from
such outer node, and (ii) update presence information associated with
each inner node that communicates, as an intermediate node, the check-in
message of the outer node.

[0085]In a feature, the presence server updates the presence information
associated with the outer node and each inner node that communicates, as
an intermediate node, the check-in message of the outer node, upon
sending an acknowledgement of receipt of the message to the outer node
along a pathway that includes each of the inner nodes that communicated
the check-in message of the outer node.

[0086]In a feature, the presence server comprises a server disposed in
electronic communication with a gateway device of the data communications
network.

[0087]In a feature, the presence server comprises a gateway server of the
data communications network.

[0088]In another aspect relating to ad hoc wireless networks in which
communications between a node of the wireless ad hoc network and a
network external thereto ("External Network") may undergo one or more
hops in the ad hoc wireless network, an identification of each node
forming the communications pathway of a message is recorded and sent with
the message as the message is communicated between nodes in the ad hoc
network. Accordingly, a message that reaches a node representing a
gateway to the External Network ("Gateway") will include with it
sufficient information so as to identify a pathway of the wireless ad hoc
data communications network by which the message has been sent and, in
particular, so as to identify each intermediate node that participated in
the communication of the message.

[0089]Another aspect of the present invention relates to a method of
maintaining presence information associated with an intermediary node.
The method includes communicating a message from a first node to a
gateway device along a pathway, the pathway including the intermediary
node; storing, in a computer readable medium at the gateway device,
information representing the pathway; communicating, to an application of
a client device, the message; updating, at the gateway device, presence
information associated with the intermediary node; communicating an
acknowledgment from the client device to the first node along the
pathway, determination of the pathway being aided by the stored
information representing the pathway; and resetting, at the intermediary
node, a timer.

[0090]In a feature of this aspect of the invention, the intermediary node
is configured to communicate a check-in message when the timer reaches a
certain value.

[0091]In a feature of this aspect of the invention, the gateway device,
the first node, and the intermediary node are part of a network utilizing
class based networking.

[0092]In a feature of this aspect of the invention, the first node and the
intermediary node utilize wake-up technology.

[0093]In a feature of this aspect of the invention, the method further
includes the steps of, prior to said step of communicating a message from
a first node, registering, by the first node, with the gateway device;
and registering, by the intermediary node, with the gateway device.

[0094]In a feature of this aspect of the invention, the gateway device,
the first node, and the intermediary node are part of a mesh network.

[0095]In a feature of this aspect of the invention, said step of resetting
a timer occurs contemporaneously with said step of communicating an
acknowledgment.

[0096]In a feature of this aspect of the invention, the gateway device
comprises a gateway router and a gateway server.

[0097]In a feature of this aspect of the invention, said step of
communicating to a client device is performed by the gateway device.

[0098]Another aspect of the present invention relates to a method of
maintaining presence information associated with an intermediary node.
The method includes receiving, at the intermediary node, a message
originating at a first node and addressed to a gateway device; storing,
in a computer readable medium at the intermediary node, information
associated with the message; communicating the message to the gateway
device; receiving, at the intermediary node, an acknowledgment of the
message; resetting a timer at the intermediary node; and communicating
the acknowledgment of the message to the first node.

[0099]In a feature of this aspect of the invention, said step of
communicating the message to the gateway device comprises communicating
the message directly to the gateway device.

[0100]In a feature of this aspect of the invention, said step of
communicating the message to the gateway device comprises communicating
the message indirectly to the gateway device via one or more other nodes.

[0101]In a feature of this aspect of the invention, said step of
communicating the acknowledgment of the message to the first node
comprises communicating the message directly to the first node.

[0102]In a feature of this aspect of the invention, said step of
communicating the acknowledgment of the message to the first node
comprises communicating the message indirectly to the first node via one
or more other nodes.

[0103]In a feature of this aspect of the invention, the method further
includes the step of, prior to said step of receiving a message
originating at a first node, registering, by the intermediary node, with
the gateway device.

[0104]In a feature of this aspect of the invention, the gateway device,
the first node, and the intermediary node are part of a mesh network.

[0105]In a feature of this aspect of the invention, the gateway device,
the first node, and the intermediary node are part of a network utilizing
class based networking.

[0106]In a feature of this aspect of the invention, the first node and the
intermediary node utilize wake-up technology.

[0107]Another aspect of the present invention relates to a network
configured to maintain presence information associated with a plurality
of nodes. The network includes a gateway device configured to communicate
an acknowledgment in response to a check-in message; a plurality of outer
nodes configured to send periodic check-in messages to the gateway
device; and a plurality of inner nodes configured to send periodic
check-in messages to the gateway device; wherein a communication from one
of the plurality of outer nodes to the gateway device has to pass through
at least one of the plurality of inner nodes on its way to the gateway
device; and wherein each of the plurality of inner nodes is configured to
reset a timer associated with the sending upon communicating a check-in
message originating at one of the outer nodes, and communicating a
corresponding acknowledgment originating at the gateway device; and
wherein the gateway device is configured to update presence information
associated with one of the plurality of outer nodes in response to
receiving a check-in message originating at the one of the plurality of
outer nodes, and update presence information associated with one of the
plurality of inner nodes in response to receiving a check-in message that
passed through the one of the plurality of inner nodes.

[0108]In a feature of this aspect of the invention, the first node and the
intermediary node utilize wake-up technology.

[0109]In addition to the aforementioned aspects and features of the
present invention, it should be noted that the present invention further
encompasses the various possible combinations and subcombinations of such
aspects and features.

BRIEF DESCRIPTION OF THE DRAWINGS

[0110]One or more preferred embodiments of the present invention now will
be described in detail with reference to the accompanying drawings,
wherein the same elements are referred to with the same reference
numerals, and wherein:

[0111]FIG. 1 illustrates a data communications network in accordance with
a preferred embodiment of the invention;

[0112]FIG. 2 illustrates the data communications network of FIG. 1 wherein
a node 13 has moved to within the coverage area of the gateway server 41;

[0114]FIG. 4 illustrates a table showing the respective number of node
transmissions for each of the sets of nodes; and

[0115]FIG. 5 illustrates, for perspective, a data communications network
having multiple user servers and client applications as well as multiple
locations, each having a gateway server.

DETAILED DESCRIPTION

[0116]As a preliminary matter, it will readily be understood by one having
ordinary skill in the relevant art ("Ordinary Artisan") that the present
invention has broad utility and application. Furthermore, any embodiment
discussed and identified as being "preferred" is considered to be part of
a best mode contemplated for carrying out the present invention. Other
embodiments also may be discussed for additional illustrative purposes in
providing a full and enabling disclosure of the present invention. As
should be understood, any embodiment may incorporate only one or a
plurality of the above-disclosed aspects of the invention and may further
incorporate only one or a plurality of the above-disclosed features.
Moreover, many embodiments, such as adaptations, variations,
modifications, and equivalent arrangements, will be implicitly disclosed
by the embodiments described herein and fall within the scope of the
present invention.

[0117]Accordingly, while the present invention is described herein in
detail in relation to one or more embodiments, it is to be understood
that this disclosure is illustrative and exemplary of the present
invention, and is made merely for the purposes of providing a full and
enabling disclosure of the present invention. The detailed disclosure
herein of one or more embodiments is not intended, nor is to be
construed, to limit the scope of patent protection afforded the present
invention, which scope is to be defined by the claims and the equivalents
thereof. It is not intended that the scope of patent protection afforded
the present invention be defined by reading into any claim a limitation
found herein that does not explicitly appear in the claim itself.

[0118]Thus, for example, any sequence(s) and/or temporal order of steps of
various processes or methods that are described herein are illustrative
and not restrictive. Accordingly, it should be understood that, although
steps of various processes or methods may be shown and described as being
in a sequence or temporal order, the steps of any such processes or
methods are not limited to being carried out in any particular sequence
or order, absent an indication otherwise. Indeed, the steps in such
processes or methods generally may be carried out in various different
sequences and orders while still falling within the scope of the present
invention. Accordingly, it is intended that the scope of patent
protection afforded the present invention is to be defined by the
appended claims rather than the description set forth herein.

[0119]Additionally, it is important to note that each term used herein
refers to that which the Ordinary Artisan would understand such term to
mean based on the contextual use of such term herein. To the extent that
the meaning of a term used herein--as understood by the Ordinary Artisan
based on the contextual use of such term--differs in any way from any
particular dictionary definition of such term, it is intended that the
meaning of the term as understood by the Ordinary Artisan should prevail.

[0120]Furthermore, it is important to note that, as used herein, "a" and
"an" each generally denotes "at least one," but does not exclude a
plurality unless the contextual use dictates otherwise. Thus, reference
to "a picnic basket having an apple" describes "a picnic basket having at
least one apple" as well as "a picnic basket having apples." In contrast,
reference to "a picnic basket having a single apple" describes "a picnic
basket having only one apple."

[0121]When used herein to join a list of items, "or" denotes "at least one
of the items," but does not exclude a plurality of items of the list.
Thus, reference to "a picnic basket having cheese or crackers" describes
"a picnic basket having cheese without crackers", "a picnic basket having
crackers without cheese", and "a picnic basket having both cheese and
crackers." Finally, when used herein to join a list of items, "and"
denotes "all of the items of the list." Thus, reference to "a picnic
basket having cheese and crackers" describes "a picnic basket having
cheese, wherein the picnic basket further has crackers," as well as
describes "a picnic basket having crackers, wherein the picnic basket
further has cheese."

[0122]Referring now to the drawings, one or more preferred embodiments of
the present invention are next described. The following description of
one or more preferred embodiments is merely exemplary in nature and is in
no way intended to limit the invention, its implementations, or uses.

[0123]Turning now to the drawings, FIG. 1 illustrates a data
communications network 10 in accordance with one of many different
preferred embodiments of the present invention. The network 10 includes a
gateway controller or gateway server 41 and a wireless data communication
device forming a remote sensor node 11 (sometimes referred to, and
hereinafter, "RSN", "RSN" or simply "node"). The wireless data
communication device of node 11 is within a communication range and,
thus, inside a coverage area, of the gateway server 41, as indicated by
the dotted line, and the wireless data communication device has
registered with the gateway sever 41 and forms node 11 of the data
communications network 10. FIG. 1 also illustrates another wireless data
communication device 13 which lies outside the coverage area of the
gateway server 41 and has not registered with the gateway server 41 and
does not form a node of the data communications network 10.

[0124]FIG. 2 illustrates data communications network 10 of FIG. 1 wherein
node 13 has moved to within the coverage area of the gateway server 41.
Upon entering the coverage area, node 13 registers or "checks-in" with
the gateway server 41, alerting the gateway server 41 to the presence of
the wireless data communication device 13 within the coverage area.
Additionally, gateway server 41 communicates 91 with a client application
on a user device, such as user server 93, via an API interface of the
gateway server 41, informing the client application of the presence of
the wireless data communication device now forming node 13 in the data
communications network. It will be appreciated that for some client
applications, the regular determination of the presence of a wireless
data communication device within the coverage area of the gateway server
41, such as by use of check-in messages, is desirable in order to allow
the client application to monitor and confirm the location of the
wireless data communication device 13. For example, each wireless data
communication device may be configured to communicate a check-in message
to the client application, via the gateway server 42, at predefined
intervals of time.

[0125]In the foregoing illustration of a preferred embodiment, it will be
appreciated that the client application serves as a "presence server" in
keeping track of presence information for the wireless data
communications device 13. The client application may serve as the
presence server for all of the wireless data communication devices or,
alternatively, a subset thereof. Moreover, the gateway server 41 also may
function as a presence server for one or more of the wireless data
communication devices. For example, all wireless data communication
devices associated with shipments for Wal-Mart may be tracked, and the
presence information thereof maintained, by a first presence server,
while those wireless data communication devices associated with shipments
for Target may be tracked, and the presence information thereof
maintained, by a second, different presence server, even though presence
information (e.g., check-in messages) are communicated over the Internet
by way of the gateway server. The locations may include each waypoint and
in-transit locations in the logistic chain between the manufacturer and
the various retail stores.

[0126]FIG. 3 illustrates the data communications network 10 of FIG. 1 in
which fifteen wireless data communication devices form nodes 11-39 (odd).
It will be appreciated that, in this implementation, communications pass
through, or "hop" along, intermediate nodes in traveling from and to
outer nodes to the gateway server; indeed, the outer nodes may be out of
range of direct radio frequency communications with the gateway server.
More specifically, FIG. 3 illustrates a check-in message originating at
node 19, which requires three "retransmissions" or hops to get from node
19 to the gateway 41. The pathway for the three hops, as illustrated in
this example, is from node 25 to node 33 via hop 14; from node 33 to node
37 via hop 16; from node 37 to gateway server 41 via hop 18. (Note that
the initial transmission 12 by node 19 to node 25 is not considered or
deemed a "hop" herein because it is the initial transmission.)

[0127]After the message has been communicated to the respective presence
server (which in this case shall be deemed to be the gateway server 41),
the gateway server 41 returns an acknowledgment (hereinafter, "ACK") of
the check-in message to the initiating node 19. The pathway by which the
ACK is communicated is the reverse of the pathway by which the check-in
message is communicated, and includes transmission 28 with hops 30, 32,
and 34.

[0128]In total, communication of a check-in message from node 19 to the
gateway server 41 requires four total node transmissions (the initial
transmission and three hops), and communication of an acknowledgment from
the gateway server 41 to the node 19 requires three node transmissions
(each a hop) with the initial transmission being by the gateway server
41.

[0129]It will be appreciated from the above description and FIG. 3 that
nodes 11,13,15 each require four hops in communicating a check-in message
to gateway server 41; nodes 17,19,21 each require three hops in
communicating a check-in message to gateway server 41; nodes 23,25,27
each require two hops in communicating a check-in message to gateway
server 41; nodes 29,31,33 each require one hop in communicating a
check-in message to gateway server 41. Nodes 35,37,39 do not require any
hops in communicating a check-in message to gateway server 41 as each
directly communicates with the gateway server 41.

[0130]The respective number of node transmissions for each of these sets
of nodes is set forth in Table 1 of FIG. 4. For example, nodes 11,13,15
each require eight hops or node retransmissions to communicate a check-in
message and receive an acknowledgment back. Multiplying these eight
required transmissions by the number of nodes, i.e. three, results in a
total of twenty-four required node retransmissions for check-in messages
from nodes 11,13,15 per check-in interval, e.g., every fifteen minutes.

[0131]It will be appreciated that having a large number of nodes with a
pathway to the gateway router 41 including a large number of hops greatly
increases the total number of node retransmissions required for check-in
messages. As can be seen in FIG. 4, the total number of node
retransmissions required for a check-in message and corresponding
acknowledgment for each of the fifteen nodes of network 10 is sixty.

[0132]The total required number of node retransmissions, in accordance
with the principal invention of the present application, is reduced as
now described.

[0133]Specifically, each communication of a check-in message preferably
includes the pathway by which the check-in message has actually be
communicated by the wireless data communication devices. Moreover, the
pathway preferably is identified by unique identifications a unique
identifier (hereinafter, "UID") of each wireless data communication
device participating in the hops. The respective UID of a node
retransmitting the message preferably is appended to the communication of
the message with each hop.

[0134]When the gateway server 41 receives the check-in message from node
19, the gateway server 41 identifies from the pathway the nodes along
which the message has hopped, i.e., through intermediate nodes 25, 33,
and 37. In particular, the gateway server 41 analyzes the message to
determine the UID of each node along the pathway. Then, rather than only
considering the check-in message of node 19, the gateway server 41
further utilizes these UIDs of the pathway to determine the presence of
these additional nodes. The presence information for each of these nodes
consequently is updated.

[0135]Importantly, the ACK that is sent to node 19 is sent along the
reverse pathway by which the check-in message was sent to the gateway
server 41. This insures that each intermediate node receives and
retransmits the ACK for delivery to node 19. In doing so, each
intermediate node thereby receives its own acknowledgement that its
presence, as indicated by the pathway information, has been acknowledged
by the gateway server 41.

[0136]In this respect, each intermediate node 25, 33, and 37 remembers
that it passed (hopped) an inbound check-in message from the initiating
node 19 and, when it passes (hops) the ACK back to the initiating node
19, the intermediate node 25, 33, and 37 uses the ACK as a positive
indication that the inbound check-in message was delivered. Based on
this, each of the intermediate nodes 25, 33, and 37 causes the check-in
interval to be reset to zero as if the respective node had sent a
check-in message itself and received back an ACK. As such, none of the
intermediate nodes will send its own check-in message until its
respective time interval for doing so (starting at the time of
retransmitting the ACK for delivery to node 19) has passed.

[0137]In will further be appreciated that, in accordance with the current
inventive aspect of the invention of the present application, messages
that are hopped need not be check-in messages of the outer nodes but,
instead, may be other types of messages.

[0138]In general, the intermediate nodes 25,33,37 now benefit from hopping
inbound messages, as each resets its chronometer (clock or timer) for
counting down its check-in interval, none need to send a check-in message
as quickly as it otherwise would have done if there had been no message
hopping. As an example, the outside nodes 11,13,15 may send check-in
messages every 15 minutes, with each of all of the other nodes serving as
intermediate nodes for the outside nodes 11,13,15, whereby check-in
messages for such intermediate nodes would not be required to be sent. In
this scenario, only twenty-four retransmissions or hops thus are
required, instead of 60 hops as set forth in table 1 of FIG. 4 (a
sixty-percent reduction!).

[0139]For perspective, the data communications network 10 is shown in FIG.
5 with respect to multiple user servers and client applications as well
as multiple locations each having a gateway server.

[0140]It will be appreciated from the above description that intelligence
within nodes and other gateways allows message information from
intermediate, hopping nodes to be utilized in reducing the overall number
of required hops in the data communications network when all nodes are
configured to send their own check-in messages.

[0141]Moreover, data communications networks in accordance with preferred
embodiments of the invention provide other benefits as well, including
allowing for a high density of nodes, extending battery life of the
nodes, reducing the number of retransmissions as well as initial
transmissions by each node, and supplying "free" application messages to
nodes when they are used as intermediate nodes.

[0142]It will be appreciated from the above description that aspects and
features in accordance one or more embodiments of the present invention
may be utilized with a wide variety of types of networks and in a wide
variety of contexts. For example, aspects and features in accordance with
embodiments of the present invention may be utilized in combination with
mesh networking or class based networking. Further, aspects and features
may be utilized to assist in first responder situations, to assist in
container tracking and monitoring, and to track and monitor equipment,
including rental construction equipment. It is intended that the class
based networking and wakeup technologies, and related features,
improvements, and enhancements, as disclosed in the references
incorporated herein, may be utilized in combination with various
embodiments and implementations of the present invention.

[0143]For example, in a preferred embodiment, a system is configured to
cause RSNs connected to a network to send quasi-periodical check-in
messages to indicate to the network that the RSN is still present (in the
RF-vicinity of a gateway). The network knows when to expect such
messages. If a defined number of these messages are not received within a
defined period, than an infrastructure of the network sends a message to
the user application that an asset associated with the silent RSN is
unaccounted for. A timer is used to determine when to send these
messages, but is reset as a result of various communication activities of
the RSN. When an RSN passes a communication from another RSN along (i.e.,
a message is being hopped and the RSN is in a communication pathway
between another RSN and a gateway), information is also passed along with
the message that allows the gateway controller or server to know that the
RSN was involved in the communication as an intermediate node. Then, when
an acknowledgment is passed back along the same pathway, the RSN knows
that the gateway controller or server is cognizant of its continued
presence. Thus, by passing a communication on along a pathway that
eventually leads to the gateway that the RSN is supposed to periodically
check in with, the RSN has essentially informed the gateway that it is
still present. Consequently, the RSN can reset its check-in timer, as
there is no need to send a check-in message when the gateway is already
aware that the RSN is still there. This methodology helps to reduce radio
activity while still allowing for monitoring of RSN presence.

[0144]Based on the foregoing description, it will be readily understood by
those persons skilled in the art that the present invention is
susceptible of broad utility and application. Many embodiments and
adaptations of the present invention other than those specifically
described herein, as well as many variations, modifications, and
equivalent arrangements, will be apparent from or reasonably suggested by
the present invention and the foregoing descriptions thereof, without
departing from the substance or scope of the present invention.

[0145]Accordingly, while the present invention has been described herein
in detail in relation to one or more preferred embodiments, it is to be
understood that this disclosure is only illustrative and exemplary of the
present invention and is made merely for the purpose of providing a full
and enabling disclosure of the invention. The foregoing disclosure is not
intended to be construed to limit the present invention or otherwise
exclude any such other embodiments, adaptations, variations,
modifications or equivalent arrangements, the present invention being
limited only by the claims appended hereto and the equivalents thereof.